This invention relates to brakes for bending sheet material such as aluminum sheet and vinyl sheet that is utilized for application as siding for buildings and the like.
In the prior U.S. Pat. Nos. 3,161,223 and 3,559,444, there are disclosed and claimed sheet metal bending brakes wherein sheet metal is clamped between an anvil member, resiliently supported on the upper arms of C-shaped members, and a clamping surface and a bending member is hinged for bending the sheet metal about the anvil member.
A problem that arises in connection with bending relatively thick or stiff sheet material is the tendency for the anvil member, which is generally L-shaped to rotate when the bending member is swung to bend the material.
Accordingly, the invention is directed to a sheet metal brake wherein the tendency for such rotation and the resultant loss of accuracy of the bend is minimized.
In accordance with the invention, at least one laterally extending projection is provided on the C-shaped members adjacent each vertical portion of the L-shaped anvil member to engage the anvil member and thereby minimize any tendency for rotation so that the bend which is made is accurate and uniform throughout.